Manchester United have added Celtic youngster Kieren Tierney to their shortlist of January transfer targets, according to reports from the Daily Record.

Jose Mourinho is reportedly eyeing the Scotland international as one of two defenders he wants to sign this month amidst injury and form problems with his current back-line.

The Portuguese manager has been unable to field a consistent back four for much of this season, but wants to change that going into the second half of the campaign. Left-back as also been a problem position for Mourinho since his arrival at Old Trafford – with midfielder Ashley Young often being utilised as a make-shift first choice.

Luke Shaw has found himself back in the United side in recent weeks amidst a suspension to Young, and while impressing, it is still thought he is free to leave Old Trafford this month after a difficult and injury plagued few seasons with the club.

Tierney, 20, has proven himself as one of Europe’s most talented young full-backs in recent years with Celtic and Scotland, winning the SPFA’s Young Player of the Year award for the last two years running.

The youngster has also established himself as first choice in the Scotland national team.

Tierney however, is understood not to be keen to leave Celtic, and the Hoops are also keen to hold on to the player who recently signed a six-year contract extension until 2023.

Should United be unable to prize Tierney away from Celtic Park, they could turn their attentions to Fulham’s Ryan Sessegnon or Juventus star Alex Sandro – although any move for the latter is expected to cost in the region of around £60 million.